Sustainable Value Report 2001/2002 - BMW Group

55% reduction in auto body weight
New material with excellent
environmental qualities
Losing weight is not only good for human
health, it also benefits the environment. When
it comes to reducing the weight of a BMW
automobile, the “diet” must not reduce vehicle
safety, comfort, or driving enjoyment.
This approach led to a technological masterpiece
in lightweight automobile construction
designed by the BMW experts at Technik GmbH
in August 2000. One of the characteristics that
make the BMW Z22 unique from an environmental
standpoint is its fuel economy. Although
in terms of comfort, performance, and interior
space the new car is comparable to a BMW
530i touring, this technological wonder uses
only 6 liters of fuel per 100 km.The 35% weight
reduction represents a quantum leap in lightweight
construction technology.
Weighing just 1,100 kg (10kg/kW), the Z22
is the world’s first Mechatronic automobile.
Mechatronic, which refers to a mechanical
system with electronic control, represents an
automotive revolution. New Steer-by-Wire and
Brake-by-Wire technologies in the Z22 replace
the mechanical steering and hydraulic brake
systems.
A team of engineering specialists developed
the 70 innovations and new composite materials
featured on the new technological tour de
force.The degree of project success borders
on the phenomenal:The lightweight Z22 virtually
launched a technological chain reaction at BMW.
Based on Z22 project results, the company
decided to work more extensively with carbon
Side frame in deep-forged steel: 47.1 kg
Z22 side space frame in CFRP material: 21.3 kg
fiber reinforced polymers (CFRP). Since then,
the BMW Group has been developing this
material for use in series production cars.
The material of tomorrow
CFRP is destined to become a familiar term for
BMW owners. In the future, they may very well
find themselves sitting in a passenger cabin
made from carbon fiber reinforced polymer.
This is one more way in which BMW demonstrates
its technological leadership in lightweight
vehicle construction. CFRP currently
shows the greatest weight saving potential in
car body construction. It is 50 percent lighter
than steel and up to 30 percent lighter than
aluminum. BMW is developing CFRP technology
as part of its Design for the Environment program.
Along with lower weight, the material is
corrosion resistant and performs extremely
well in vehicle crash testing.
International project team
An international project team made up of
members from all BMW divisions is currently
working on the development of CFRP for lightweight,
series production auto bodies.This
process is managed by the experts at the BMW
Research and Innovation Center in Munich.
One thing is already clear: BMW will only
start using CFRP in series production when it
becomes cost neutral compared to aluminum.
Along with environmental criteria, economy is
an important aspect in the development of new
lightweight materials.
Far left: Technology prototype Z22
Left: Z22, central control panel
Right: Z22, multi-function steering wheel
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